Crossflow Turbine

Abstract

To provide a low-cost crossflow turbine that can suppress the generation of cavitation and enhance turbine efficiency.SOLUTION: A crossflow turbine 1 according to the present invention includes: a casing 10; a runner 12 rotatably arranged in the inside of the casing 10; an inflow passage 14 allowing the inflow of liquid; and a nozzle 16 communicated with the inflow passage 14 and circulating liquid toward the runner 12. The nozzle 16 is supported by the casing 10, and has a movable guide vane 18 for adjusting the flow quantity of liquid in the inside thereof, and also has a first wall part 16A disposed facing one end 18a side of the guide vane 18, and a second wall part 16B disposed facing the other end 18b side of the guide vane 18. The second wall part 16B has an opening angle regulating part 16x for regulating a nozzle opening angle in a tip part 16a, and a plurality of kinds of parts having different shapes of the opening angle regulating part 16x are disposed, and one part corresponding to the flow quantity is selected and detachably fixed to the casing 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a crossflow turbine having a runner rotatably disposed inside a casing. [Background technology]

[0002] Cross-flow turbines that are driven by the flow of liquid, such as water, and are used, for example, in hydroelectric power generation, have been known for some time (see Patent Document 1: Japanese Patent Laid-Open Publication No. 4-179865). A cross-flow turbine is configured with a runner that is rotatably supported and has a plurality of blades provided in the circumferential direction. When liquid flows into the runner from the outside to the inside, and when liquid flows out of the runner from the inside to the outside, the liquid hits the blades, causing the runner to rotate. In general, cross-flow turbines have the characteristics of being low in manufacturing cost and being able to generate power even when the flow rate changes greatly. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-179865 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, as the effective use of natural energy is being called for, so-called small-scale hydroelectric power generation, which generates electricity by driving a cross-flow turbine with the water flow of an irrigation canal, etc., has been attracting more and more attention. In order to put it into practical use, the challenges are to ensure economic viability, specifically, to improve the efficiency of converting water flow energy into rotational energy (hereinafter sometimes referred to as "turbine efficiency"), and to reduce costs (manufacturing costs and maintenance costs).

[0005] Taking agricultural irrigation canals as an example, as shown in the graph in Figure 3, the reality is that due to relationships with permitted water volumes and other factors, the amount of water varies greatly throughout the year between the non-irrigation season (a), the plowing season (b), and the irrigation season (c). More specifically, it is not rare for the difference in water volume during the plowing season (b), when the amount of water is at its highest, to be more than three times that of the non-irrigation season (a), when the amount of water is at its lowest. Therefore, when using such agricultural irrigation canals as a water source, the challenge is how to increase efficiency, particularly when the amount of water is low, in other words, how to increase turbine efficiency during partial load operation.

[0006] In this regard, the crossflow turbine exemplified in Patent Document 1, etc., is equipped with a split guide vane (guide member) located upstream of the runner, which controls (adjusts) the amount of water flowing into the runner, enabling operation over a wide range of flow rates.

[0007] However, in the case of a configuration with a split guide vane as described above, the structure of both the guide vane itself and the drive mechanism for split driving becomes complicated, which increases both manufacturing and maintenance costs. In addition, a partition wall must be provided at the guide vane split section of the inlet passage, which causes energy loss due to friction between the partition wall surface and the water flow.

[0008] Furthermore, although the flow rate can be adjusted to a certain extent (adjustment range) by dividing and driving the guide vanes, if the flow rate is extremely restricted, more cavitation may occur on the surface of the runner blades or in the area near the surface. This cavitation can cause erosion on the runner blades and the casing wall, and can also cause noise and vibration in the runner itself, ultimately shortening the bearing life of the rotating shaft. Therefore, the issue is how to suppress the occurrence of cavitation. [Means for solving the problem]

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a cross flow turbine which can achieve a simple device configuration and reduced costs by adopting an integrated guide vane structure, can suppress the occurrence of cavitation by using a nozzle configuration which allows a wide range of flow rate adjustment without drastically restricting the flow rate, and can improve turbine efficiency, especially during partial load operation, compared to a split guide vane structure.

[0010] In one embodiment, the above problem is solved by the solution means disclosed below.

[0011] The disclosed cross-flow turbine is a cross-flow turbine having a casing and a runner rotatably arranged inside the casing, and is equipped with an inlet passage for introducing liquid, and a nozzle connected to the inlet passage for flowing the liquid toward the runner, wherein the nozzle is supported by the casing and has a movable guide vane therein for adjusting the flow rate of the liquid passing through, and has a first wall portion provided opposite one end side of the guide vane and a second wall portion provided opposite the other end side of the guide vane, wherein the second wall portion has an opening angle defining portion at its tip portion for defining a nozzle opening angle, and a plurality of types of opening angle defining portions with different shapes are provided, and one corresponding to the passing flow rate is selected and removably fixed to the casing. Effect of the Invention

[0012] According to the disclosed cross flow turbine, by providing an integral guide vane structure, a simple device configuration can be realized, and manufacturing and maintenance costs can be reduced. For example, even when using water from a water source whose liquid flow rate varies greatly, compared to a configuration provided with a conventional split guide vane structure, a wide range of flow rate adjustment can be achieved without drastically restricting the flow rate, and turbine efficiency can be improved. [Brief description of the drawings]

[0013] [Figure 1]1 is a cross-sectional view showing an example of a cross flow turbine according to a first embodiment of the present invention. [Diagram 2] FIG. 3 is a cross-sectional view showing another example of the cross flow turbine according to the first embodiment of the present invention. [Diagram 3] 1 is a graph showing a schematic diagram of annual fluctuations in water volume in an irrigation canal. [Figure 4] 1 is a graph illustrating a comparison of turbine efficiency between a crossflow turbine according to an embodiment of the present invention and a crossflow turbine according to a conventional embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing an example of a cross flow turbine according to a second embodiment of the present invention. [Figure 6] FIG. 11 is a cross-sectional view showing another example of a cross flow turbine according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (First embodiment) Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. Figures 1 and 2 are both side cross-sectional views (schematic views) showing an example of a cross-flow turbine 1 according to this embodiment, each of which is an example in which the configuration of a nozzle 16 (specifically, a second wall portion 16B) is different. In all the drawings for explaining the embodiment, members having the same function are given the same reference numerals, and repeated explanations thereof may be omitted.

[0015] The cross-flow turbine 1 is a device that converts the liquid flow energy of the liquid flowing inside into rotational energy and extracts it. In outline, the cross-flow turbine 1 includes an inlet 14 that communicates with an intake port (not shown) and allows the liquid (shown by dots in the figure) to flow in, a casing 10 in which a runner 12 rotatably supported inside is disposed, a nozzle 16 that communicates with the inlet 14 and allows the liquid to flow toward the runner 12, and an outlet 20 that communicates with an outlet port (not shown) and allows the liquid that has passed through the runner 12 to flow out. With this configuration, the liquid that has flowed into the casing 10 can hit the runner 12 to rotate the runner 12. That is, this rotational force can be output and used as a driving force for a generator or the like. In this embodiment, the "liquid" is described by taking "water" that has its source in an irrigation channel or a small river as an example, but is not limited thereto.

[0016] Next, each component of the cross flow turbine 1 according to this embodiment will be described. First, the inflow passage 14 is a member that is connected to a nozzle 16 described below to form a water flow path. Note that the inflow passage 14 is made of, for example, a metal material (e.g., general steel, aluminum alloy, stainless steel, brass, etc.).

[0017] Next, the nozzles 16 are supported (specifically, connected by using fastening bolts) by a substantially box-shaped casing 10 so that their internal spaces communicate with each other. A movable guide vane 18 for adjusting the flow rate of water passing through is disposed inside the nozzle 16. The nozzle 16 also includes a first wall portion 16A provided opposite one end 18a of the guide vane 18, and a second wall portion 16B provided opposite the other end 18b of the guide vane 18. The detailed configuration of the nozzle 16 will be described later.

[0018] The guide vane 18 according to the present embodiment is a so-called rotating (swinging) guide vane 18, and is configured to include a rotating shaft 18A supported by the nozzle 16 and a guide body 18B provided along the axial direction of the rotating shaft 18A. This allows the guide vane 18 to rotate (swing) about the rotating shaft 18A, and the distance between one end 18a of the guide vane 18 (specifically, the guide body 18B) and the first wall portion 16A and the distance between the other end 18b of the guide vane 18 (specifically, the guide body 18B) and the second wall portion 16B can be changed. In other words, since the flow path cross-sectional area inside the nozzle 16 can be changed, the flow rate (passing flow rate) of water flowing through the nozzle 16 and flowing into the runner 12 can be adjusted.

[0019] Specifically, when the rotary shaft 18A is rotated to bring one end 18a of the guide body 18B close to the first wall portion 16A and the other end 18b close to the second wall portion 16B, the flow rate of water passing through the nozzle 16 can be reduced. Conversely, when the one end 18a of the guide body 18B is moved away from the first wall portion 16A and the other end 18b is moved away from the second wall portion 16B, the flow rate of water passing through the nozzle 16 can be increased. For example, in Figures 1 and 2, the set position P1 of the guide vane 18 shown by the dashed line is a position at which the passing flow rate is minimum (in this case, the fully closed state and the passing flow rate is zero), and the set position P2 of the guide vane 18 shown by the solid line is a position at which the passing flow rate is maximum. As shown in the figure, water flowing through the nozzle 16 flows through two flow paths (regions), a flow path R1 closer to the first wall portion 16A and a flow path R2 closer to the second wall portion 16B relative to the guide vane 18, before flowing into the runner 12. The movable guide vane 18 is not limited to a rotating (swinging) type configuration, and may be a known sliding type configuration (not shown).

[0020] Moreover, the guide vane 18 according to this embodiment has an integral structure that is not divided in the direction along the rotation shaft 12A of the runner 12 (i.e., in the direction parallel to the axial direction of the rotation shaft 12A). Therefore, a simple structure can be realized, and manufacturing and maintenance costs can be reduced. On the other hand, the nozzle configuration (described later) unique to the present invention enables a wide range of flow rate adjustment equal to or greater than that of conventional divided guide vane structures.

[0021] Next, the runner 12 is configured to include a rotating shaft 12A and a plurality of blades 12B. In this embodiment, the rotating shaft 12A is rotatably supported by the casing 10, and is disposed so that its axial direction is parallel to the horizontal direction. This allows the water flowing through the nozzle 16 to flow into the runner 12, causing the runner 12 to rotate (the principle of rotation will be described later). The clearance between the closest portions of the runner 12 (specifically, the blades 12B) and the nozzle 16 (specifically, the first wall portion 16A and the second wall portion 16B) is set to about 1 mm, for example.

[0022] Here, the blades 12B are arranged at equal intervals in the circumferential direction around the rotating shaft 12A. The blades 12B form the runner 12 into a generally cylindrical shape having a space 12C inside. As an example, the blades 12B are fixed so as to be sandwiched between two disk members (not shown) connected to both ends of the rotating shaft 12A in the axial direction. In this embodiment, the rotating shaft 12A is provided so as to penetrate the space 12C, but this is not limited thereto, and the rotating shaft 12A may be provided only at both ends supported by the casing 10 (not shown).

[0023] Moreover, each blade 12B is plate-like, and the cross-sectional shape in the direction perpendicular to the axial direction of the rotating shaft 12A is formed into a curved shape that is convex in the direction of rotation. As a result, when water flows into the space 12C from the radially outward direction, and when water flows out from the space 12C to the radially outward direction, the water flowing along the concave portion of the runner 12 applies a circumferential (rotational) force to the blade 12B, causing the runner 12 to rotate in the direction of arrow A in Figures 1 and 2.

[0024] Furthermore, in this embodiment, the runner 12 is disposed so that the axial direction of the rotating shaft 12A is parallel to the horizontal direction, and the nozzle 16 is disposed vertically above the runner 12, and the outlet channel 20 is disposed vertically below the runner 12. With this configuration, the water that has passed through the nozzle 16 can be made to flow vertically downward into the runner 12. That is, gravity acts on the water that flows from the nozzle 16 into the runner 12. Therefore, in addition to the pressure of the water passing through the nozzle 16, gravity acting on the water can also be used as a force (energy) for rotating the runner 12.

[0025] The runner 12 (particularly the blades 12B) and the aforementioned guide vane 18 (particularly the guide body 18B) are, as an example, made of a metal material (e.g., stainless steel) that has a relatively high mechanical strength. This makes it possible to increase durability against erosion caused by cavitation and abrasion by sediment. However, the material is not limited to this, and other metal materials (e.g., titanium alloys, brass), other resin materials (carbon fiber reinforced plastics), etc. may also be used.

[0026] Next, the outflow path 20 constitutes a flow path that causes the water that has passed through the runner 12 to flow toward an outlet (not shown). In this embodiment, the outflow path 20 is formed by a space adjacent to the runner 12 (the portion on the outflow side) in the casing 10. As an example, the casing 10 is formed using a metal material (e.g., general steel, aluminum alloy, stainless steel, titanium alloy, brass, etc.). As a result, the water that has flowed out from the runner 12 flows toward the outside of the device through the outflow path 20. As another example, the outflow path 20 may be formed using a tubular member separate from the casing 10 and connected to the casing 10 (not shown).

[0027] The casing 10 is provided with a ventilation valve (not shown) for communicating the internal outflow passage 20 with the outside to allow ventilation. This has the effect of making the flow of water passing through the runner 12 and flowing out into the outflow passage 20 smoother.

[0028] Next, the configuration of the nozzle 16, which is characteristic of this embodiment, will be described in detail. The second wall portion 16B constituting the nozzle 16 is provided with an opening angle defining portion 16x at the tip portion 16a, which defines the nozzle opening angle. Here, the "nozzle opening angle" refers to the opening amount (in this case, the angle) of the opening that sets the flow rate of water that flows from the inflow channel 14 through the nozzle 16 and into the runner 12, as exemplified by θ1 in FIG. 1 and θ2 in FIG. 2.

[0029] The second wall portion 16B of the nozzle 16 according to this embodiment is provided with a plurality of types of opening angle defining portions 16x with different shapes, and one of them is selected according to the flow rate of the water flowing into the runner 12 and is configured to be detachable from the casing 10. As a selection criterion, when the flow rate is relatively small, the second wall portion 16B having the opening angle defining portion 16x shaped to reduce the nozzle opening angle (for example, θ1=80° in FIG. 1) is selected, and when the flow rate is relatively large, the second wall portion 16B having the opening angle defining portion 16x shaped to increase the nozzle opening angle (for example, θ2=110° in FIG. 2) is selected, and the nozzle 16 is configured (FIGS. 1 and 2 are merely examples for explanation, and are not limited to two types). In this embodiment, the second wall portion 16B is configured separately from the first wall portion 16A, but as another example, they may be configured integrally.

[0030] In addition, the second wall portion 16B is processed by aluminum die-casting mold manufacturing technology using an aluminum alloy as a material. Therefore, compared with conventional nozzle structures using iron-based materials, stainless steel, etc., the weight of the device can be significantly reduced. In addition, since even a complicated outer surface shape can be processed precisely and at low cost, it is possible to realize a nozzle 16 (second wall portion 16B) having a shape that has less resistance to the water flowing through it and less cavitation. However, the second wall portion 16B can also be made of a metal material other than aluminum alloy (e.g., stainless steel, titanium alloy, brass, etc.). On the other hand, when the first wall portion 16A is integral with the second wall portion 16B, it is made of the same metal material as the second wall portion 16B, and when it is separate, it may be made of the same metal material (aluminum alloy) as the second wall portion 16B or a different metal material (e.g., stainless steel, titanium alloy, brass, etc.) as the second wall portion 16B.

[0031] According to the above configuration, from among a plurality of types of nozzles 16 (in this embodiment, the second wall portion 16B) having different opening angle defining portions 16x of the tip portion 16a, an appropriate nozzle 16 (second wall portion 16B) corresponding to the flow rate of water flowing into the runner 12 can be selected and attached to the casing 10. Therefore, even if the flow rate varies greatly depending on the season, such as the water flow of an agricultural irrigation channel, the flow rate of water flowing into the runner 12 can be adjusted to be appropriate. Specifically, in the non-irrigation season, a nozzle 16 (second wall portion 16B) having a long tip portion 16a, i.e., a nozzle 16 having an opening angle defining portion 16x with a small nozzle opening angle may be selected and attached (see FIG. 1). On the other hand, in the puddling season and irrigation season, a nozzle 16 (second wall portion 16B) having a short tip portion 16a, i.e., a nozzle 16 having an opening angle defining portion 16x with a large nozzle opening angle may be selected and attached (see FIG. 2). However, since the flow rate of the water source changes depending on factors such as the weather at any time of the year, more optimal flow rate adjustment is possible by also using the guide vane 18 to adjust for small changes in flow rate.

[0032] In addition, even if maintenance work to replace the nozzle 16 becomes necessary due to erosion, abrasion by sediment, or the like, the work can be completed by simply removing and attaching the second wall portion 16B. Therefore, compared to a configuration in which the entire nozzle 16 must be replaced, the maintenance work is easier and the cost of the parts to be replaced can be kept low.

[0033] In addition, when the amount of inflow into the nozzle 16 is small, the amount of inflow can be reduced by providing the second wall portion 16B having a long tip portion 16a, so that the amount of inflow can be adjusted without excessively reducing the guide vane 18. Therefore, by not excessively reducing the guide vane 18, the gap between the guide vane 18 and the blade 12B of the runner 12 does not become extremely narrow, so that the occurrence of cavitation and erosion due to high-speed water flow can be suppressed. In this way, since cavitation, which frequently occurs when the flow rate is extremely reduced, can be suppressed, the occurrence of problems due to cavitation can be prevented. Specifically, the occurrence of erosion (erosion) in the guide vane 18 and the blade 12B of the runner 12 can be prevented. In addition, the occurrence of noise and vibration in the runner 12 itself and the resulting reduction in the bearing life of the rotating shaft 12A can be prevented.

[0034] Furthermore, there is no need to separately drive the guide vanes 18 as in the conventional method. Therefore, a non-separate integral structure can be adopted for the guide vanes 18 in the direction along the rotation axis 12A of the runner 12. This allows for a simple structure, and reduces manufacturing and maintenance costs.

[0035] Here, the graph in FIG. 4 shows the results of a relative comparison of turbine efficiency between the case of adopting the nozzle replacement method according to the present invention, i.e., a method in which multiple types of nozzles 16 (in this embodiment, the second wall portion 16B) are prepared and an appropriate one is selected according to the passing flow rate and attached to the casing 10 (shown by the dashed line in FIG. 4), and the case of adopting a conventional method in which a guide vane with a divided structure is used to adjust the flow rate according to the passing flow rate (shown by the solid line in FIG. 4). Here, the horizontal axis of the graph is the flow rate of the inflowing water (passing flow rate), and the vertical axis is the relative turbine efficiency. Note that in the region near the flow rate ratio of 100% in FIG. 4, the present embodiment and the conventional embodiment have common (almost common) results, and are therefore shown by a single dashed line.

[0036] As shown in the figure, the conventional split-structure guide vane system responds to flow rate changes by switching the width at which the water flows into the runner, which has the disadvantage of reducing the effective width of the runner and decreasing turbine efficiency. On the other hand, the nozzle replacement system according to the present invention has the advantage that the effective width of the runner 12 is always operated at its maximum width, so the decrease in turbine efficiency is relatively small.

[0037] Next, the operation of the cross flow turbine 1 of this embodiment will be described. As shown in Figures 1 and 2, first, water taken in from an intake (not shown) flows through an inlet 14 and into a nozzle 16. At this time, the flow rate of the water flowing through the nozzle 16 can be adjusted by controlling the position (opening) of a guide vane 18 provided in the nozzle 16.

[0038] Next, the water that has passed through the nozzle 16 flows into the runner 12. At this time, the passing flow rate flowing into the runner 12 can be adjusted by the magnitude of the nozzle opening angle set by the opening angle defining portion 16x provided at the tip 16a of the nozzle 16 (in this embodiment, the second wall portion 16B). As described above, since an appropriate nozzle 16 (second wall portion 16B) can be selected according to the passing flow rate, and since the nozzle 16 is configured to be detachable from the casing 10, it can be suitably applied to a water source whose flow rate fluctuates (increases or decreases) significantly.

[0039] Next, the water that has flowed into the runner 12 flows out of the runner 12. At this time, both the inflowing water and the outflowing water generate force components that press the concave portions of the blades 12B in the circumferential direction (rotational direction), causing the runner 12 to rotate in the direction of arrow A, which can be output as a rotational driving force via the rotating shaft 12A.

[0040] As described above, in this embodiment, the arrangement of the runner 12 allows the water flowing through the nozzle 16 to flow vertically downward into the runner 12. Therefore, as the force (energy) for rotating the runner 12, in addition to the pressure of the water flowing through the nozzle 16, the gravity acting on the water can also be used.

[0041] Next, the water flowing out from the runner 12 flows through the outlet passage 20 toward the discharge port (not shown). The above is an overview of the operation of the cross flow turbine 1.

[0042] Second embodiment Next, a cross flow turbine 1 according to a second embodiment of the present invention will be described. The cross flow turbine 1 according to this embodiment has a basic configuration similar to that of the first embodiment described above, but differs in particular in the configuration of the nozzle 16. This embodiment will be described below, focusing on the differences. Here, both Fig. 5 and Fig. 6 are side cross-sectional views (schematic views) showing examples of the cross flow turbine 1 according to this embodiment, and each is an example in which the configuration of the nozzle 16 (specifically, the tip portion 16a of the second wall portion 16B) is different.

[0043] In the nozzle 16 according to this embodiment, the second wall portion 16B has a divided structure. Specifically, the nozzle 16 includes a base portion 16b that is fixed to the casing 10 (for example, connected using a fastening bolt), and a tip portion 16a that is formed separately from the base portion 16b and configured to be detachable from the base portion 16b.

[0044] The tip portion 16a is provided with an opening angle defining portion 16x that defines the nozzle opening angle. In this embodiment, the tip portion 16a is provided with a plurality of different types of opening angle defining portions 16x having different shapes, and one of the opening angle defining portions 16x is selected according to the flow rate of water passing through the nozzle 16 and is attached to the base portion 16b. As a method for attaching (fixing) the tip portion 16a to the base portion 16b, for example, a method of connecting them using a fastening bolt is used.

[0045] The selection criteria for the opening angle defining portion 16x are the same as those in the first embodiment described above, and when the passing flow rate is relatively small, the tip portion 16a having the opening angle defining portion 16x shaped to reduce the nozzle opening angle (as an example, θ3=80° in FIG. 5) is selected, and when the passing flow rate is relatively large, the tip portion 16a having the opening angle defining portion 16x shaped to increase the nozzle opening angle (as an example, θ4=110° in FIG. 6) is selected, thereby forming the second wall portion 16B of the nozzle 16 (FIGS. 5 and 6 are merely examples for the purpose of explanation, and are not limited to these two types).

[0046] According to this configuration, it is possible to obtain the same effect as in the first embodiment. That is, even when the flow rate of water varies greatly depending on the season, such as the water flow of an agricultural waterway, the flow rate of water flowing into the runner 12 can be adjusted appropriately.

[0047] In particular, the tip portion 16a is preferably formed using a material having higher mechanical strength than the base portion 16b. As an example, the base portion 16b is formed using an aluminum alloy, and the tip portion 16a is formed using stainless steel having relatively high mechanical strength. The tip portion 16a of the second wall portion 16B is a member that constitutes the lower surface inside the nozzle 16, and therefore has a problem that it is particularly prone to wear due to sediment. To address this problem, the base portion 16b is made of a lightweight and easily processed aluminum alloy, while the tip portion 16a is made of stainless steel having high mechanical strength, thereby improving durability against wear due to sediment. This is also effective against erosion. The material of the tip portion 16a is not limited to stainless steel, and other metal materials (e.g., titanium alloys) and other resin materials (carbon fiber reinforced plastics) may also be used.

[0048] According to the configuration of this embodiment, even if maintenance work to replace the nozzle 16 becomes necessary due to erosion, abrasion by sediment, etc., the work can be completed by simply removing and attaching the tip portion 16a. Therefore, the maintenance work is easier than in the first embodiment described above, and the cost of the parts to be replaced can be kept low.

[0049] In this embodiment, the base portion 16b is configured as a separate body from the casing 10, but as another example, they may be configured as an integral body. Also, the base portion 16b is configured as a separate body from the first wall portion 16A, but as another example, they may be configured as an integral body.

[0050] As described above, the disclosed cross flow turbine has an integral guide vane structure, which allows for a simple device configuration and reduces manufacturing and maintenance costs. Furthermore, even when using water from a water source with a large fluctuation in flow rate, the cross flow turbine can adjust the flow rate over a wide range without drastically restricting the flow rate, and can improve turbine efficiency, compared to a conventional configuration with a split guide vane structure.

[0051] The present invention is not limited to the above-described embodiment, and may be modified in various ways. As an example, the configuration in which the rotation axis of the runner is arranged parallel to the horizontal direction has been described, but the present invention is not limited to this, and may also be applied to a configuration in which the rotation axis of the runner is arranged parallel to the vertical direction.

[0052] In addition, although the water source is described as being, for example, an irrigation channel or a small river, the water source is not limited to this, and it goes without saying that the device can be operated using a liquid other than water. [Explanation of symbols]

[0053] 1 Crossflow turbine 10 Casing 12 Runner 14 Inflow channel 16 Nozzles 16A 1st wall 16B Second wall 16x Opening angle specification 18 ガイドベーン 20 Outflow

Claims

1. A cross flow turbine comprising a casing and a runner rotatably disposed inside the casing, An inflow path for introducing liquid; a nozzle communicating with the inlet passage for causing the liquid to flow toward the runner; the nozzle is supported by the casing, has a movable guide vane therein for adjusting a flow rate of the liquid passing through, and has a first wall portion provided opposite one end side of the guide vane and a second wall portion provided opposite the other end side of the guide vane, The second wall portion has an opening angle defining portion at a tip portion thereof for defining a nozzle opening angle, and a plurality of types of opening angle defining portions having different shapes are provided, and one of the opening angle defining portions is selected according to the passing flow rate and is detachably fixed to the casing. A crossflow turbine characterized by:

2. A cross flow turbine comprising a casing and a runner rotatably disposed inside the casing, An inflow path for introducing liquid; a nozzle communicating with the inlet passage for causing the liquid to flow toward the runner; the nozzle is supported by the casing, has a movable guide vane therein for adjusting a flow rate of the liquid passing through, and has a first wall portion provided opposite one end side of the guide vane and a second wall portion provided opposite the other end side of the guide vane, the second wall portion has an opening angle defining portion at a tip portion thereof for defining a nozzle opening angle, The tip portion is formed separately from the base portion, and a plurality of types of the opening angle defining portion having different shapes are provided, and one of the types is selected according to the passing flow rate and is detachably fixed to the base portion. A crossflow turbine characterized by:

3. The tip portion is formed using a material having a higher mechanical strength than the base portion. The cross flow turbine according to claim 2 .

4. The second wall portion is configured such that a shape of the opening angle determining portion is selected to increase the nozzle opening angle when the passing flow rate is relatively large, and a shape of the nozzle opening angle is selected to decrease the nozzle opening angle when the passing flow rate is relatively small. The cross flow turbine according to any one of claims 1 to 3,

5. the second wall portion has a nozzle opening angle set in accordance with a flow rate of the liquid flowing into the runner, The guide vane is configured to be used in combination to adjust the flow rate of the liquid under conditions in which the nozzle opening angle is set. The cross flow turbine according to any one of claims 1 to 3,

6. The guide vane has an integral structure that is not divided in the direction along the rotation axis of the runner. The cross flow turbine according to any one of claims 1 to 5,

Images